1. Field of The Invention
The present invention relates generally to an oil pump for automotive applications. Particularly, the present invention relates to an oil pump in which flow rate reduction is prevented.
2. Description of The Prior Art
A conventional oil pump is comprised basically of a pump casing housing rotatable crankshaft. An inner rotor with outwardly projecting tooth portions is mounted on the crankshaft, the tooth portions of the inner rotor mesh, on one side thereof, with inwardly projecting teeth provided on an outer rotor for causing the outer rotor to rotate, thus pumping oil from an intake port provided on one side of the inner and outer rotors to a discharge port on the opposite side. However, because the oil is transferred in pockets formed in-between the teeth of the inner and outer rotor at a lower portion where the engagement therebetween is minimum, there is a tendency for oil to leak from between the teeth at a point just before a fully closed position when the oil pocket is transferred. Thus, the discharge volume of the pump may vary undesirably and the flow from the pump may become unstable.